feat(bindings)!: add RVM/Program support across FFI and language bindings (#565)

- FFI: add RVM/Program APIs, execution state accessors, HostAwait handling, and buffer/result helpers in rvm.rs, common.rs, engine.rs.
- Compiler: emit HostAwait for __builtin_host_await in function_calls.rs.
- RVM tests: add HostAwait regression cases and extend harness for suspend/resume responses in host_await.yaml and mod.rs.
- C/C++: add RVM tests/examples and wrapper updates in rvm_tests.c, rvm_tests.cpp, regorus.hpp, plus CMake wiring.
- C#: add Program/Rvm bindings, SafeHandle/PInvoke, tests, and example usage in Regorus, RvmProgramTests.cs, Program.cs, and README updates.
- Go: add Program/Rvm bindings, tests, and examples in rvm.go, rvm_test.go, main.go.
- Java: add Program/Rvm bindings, JNI glue, and examples in lib.rs, regorus, Test.java.
- Python: add Program/Rvm bindings and examples in lib.rs, test.py.
- WASM: add Program/Rvm bindings and examples in lib.rs, test.js.
- Tooling: wire binding tests in xtask and ignore generated Java artifacts in .gitignore.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

bindings/csharp/Regorus/SafeHandles.cs

@@ -87,4 +87,100 @@ namespace Regorus
             return true;
         }
     }
+
+    internal sealed class RegorusProgramHandle : SafeHandleZeroOrMinusOneIsInvalid
+    {
+        private RegorusProgramHandle() : base(ownsHandle: true)
+        {
+        }
+
+        internal static RegorusProgramHandle Create()
+        {
+            unsafe
+            {
+                var raw = Internal.API.regorus_program_new();
+                if (raw is null)
+                {
+                    throw new InvalidOperationException("Failed to create Regorus program.");
+                }
+
+                var handle = new RegorusProgramHandle();
+                handle.SetHandle((IntPtr)raw);
+                return handle;
+            }
+        }
+
+        internal static RegorusProgramHandle FromPointer(IntPtr pointer)
+        {
+            if (pointer == IntPtr.Zero)
+            {
+                throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
+            }
+
+            var handle = new RegorusProgramHandle();
+            handle.SetHandle(pointer);
+            return handle;
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            if (!IsInvalid && !IsClosed)
+            {
+                unsafe
+                {
+                    Internal.API.regorus_program_drop((Internal.RegorusProgram*)handle);
+                }
+                SetHandle(IntPtr.Zero);
+            }
+            return true;
+        }
+    }
+
+    internal sealed class RegorusRvmHandle : SafeHandleZeroOrMinusOneIsInvalid
+    {
+        private RegorusRvmHandle() : base(ownsHandle: true)
+        {
+        }
+
+        internal static RegorusRvmHandle Create()
+        {
+            unsafe
+            {
+                var raw = Internal.API.regorus_rvm_new();
+                if (raw is null)
+                {
+                    throw new InvalidOperationException("Failed to create Regorus RVM.");
+                }
+
+                var handle = new RegorusRvmHandle();
+                handle.SetHandle((IntPtr)raw);
+                return handle;
+            }
+        }
+
+        internal static RegorusRvmHandle FromPointer(IntPtr pointer)
+        {
+            if (pointer == IntPtr.Zero)
+            {
+                throw new ArgumentException("Pointer cannot be zero.", nameof(pointer));
+            }
+
+            var handle = new RegorusRvmHandle();
+            handle.SetHandle(pointer);
+            return handle;
+        }
+
+        protected override bool ReleaseHandle()
+        {
+            if (!IsInvalid && !IsClosed)
+            {
+                unsafe
+                {
+                    Internal.API.regorus_rvm_drop((Internal.RegorusRvm*)handle);
+                }
+                SetHandle(IntPtr.Zero);
+            }
+            return true;
+        }
+    }
 }